1. Field of the Invention
The present invention relates to a display apparatus, and more particularly, to a display apparatus that needs a backlight apparatus such as a liquid crystal display.
2. Description of the Related Art
Generally, in a conventional liquid crystal display, a backlight apparatus is positioned behind a liquid crystal display element. Display contents on the liquid crystal display element can be seen by light from the backlight apparatus. In such a liquid crystal display apparatus, the backlight apparatus is incorporated in a housing that accommodates the liquid crystal display element.
The backlight apparatus includes a light-emitting source such as a linear fluorescent tube, for example. A tabular light guide plate is provided adjacent to the light-emitting source. Light from the light-emitting source is incident on the tabular light guide plate, spreads and diffuses within the light guide plate, and is emitted from a whole surface of the light guide plate toward the liquid crystal display element.
The light-emitting source emits light by being provided with electric power. Accordingly, electric wires for providing the electric power are connected to the light-emitting source. In many cases, a linear fluorescent tube is used as the light-emitting source since it is necessary to efficiently emit the light with a small amount of electrical power. Thus, relatively high voltage from 800V to 1000v is applied to the light-emitting source through the electric wires.
In the backlight apparatus using the linear fluorescent tube as mentioned above, the light-emitting source and light guide plate are accommodated in a case. In order to reduce a thickness of the backlight apparatus, a metal case is used in many instances. A power supply circuit such as an inverter circuit for providing power to be supplied to the fluorescent tube is provided behind the metal case. Thus, in order to provide the power to the light-emitting source, coated electric wires connect the inverter circuit and the fluorescent tube. Since size including thickness of the liquid crystal display apparatus including the backlight apparatus is reduced, a part of the coated wires may extend close to or contact the metal case.
The coated wires are coated by an insulating layer of vinyl or the like, for example. For this reason, an electric short does not occur when the coated wires contact the metal case. However, when the coating is thin, it is conceivable that the current slightly leaks from the coated wires to the metal case. When the current leaks in this manner, the voltage applied to the fluorescent tube is decreased, and a problem occurs in that sufficient luminescent intensity (brightness) as the backlight apparatus is not obtained.